Skewing arrangement for plate cylinder and form rollers in printing press



J n 30, 96 c. J. HERMACH ETAL.

3,366,047 SKEWING ARRANGEMENT FOR PLATE CYLINDER AND FORM ROLLERS INPRINTING PRESS 5 Sheets-Sheet 1 Filed Feb. 23, 1967 liq:

c. J. HERMACH ETAL 3,366,047 SKEWING ARRANGEMENT FOR PLATE CYLINDER ANDFORM ROLLERS IN PRINTING PRbSS Jan. 30, 1968 3 Sheets-Sheet 2 Filed Feb.23, 1967 6 1 5 1r MW M Wm 2 .M %m A N mm a W #5 W ,Jam. 30, 1968 c. J.HERMACH ETAL ,3 6,

SKEWING ARRANGEMENT FOR PLATE CYLINDER AND FORM ROLLERS IN PRINTINGPRESS 5 Sheets-Sheet 5 Filed Feb. 23, 1967 United States Patent ABSTRACTOF THE DISCLOSURE A printing press having a plate cylinder which ismounted for slight skewing movement relative to the web to obtainregister between successive printed impressions and which has provisionsfor automatically maintaining the associated form rollers in properrolling engagement with the plates and ink drum over the range of skewadjustment.

For precise register of an impression relative to other impressionsalready on the web or to impressions to be subsequently impressed on theweb, provision is often made for cocking or skewing the axis of theplate cylinder relative to the web while the press is in operation. Toassure the even distribution of ink and water to the plate cylinder inits shifted position, the ink and water form rollers engaging the platecylinder must be correspondingly skewed to maintain their alinement andcontact pressure with the plate cylinder.

Typically, the ink and water form rollers in such a press are subjectedto throw-off whereby the form rollers are moved to a position spacedfrom the periphery of the plate cylinder. It is desirable that theseform rollers subsequent- 1y return to the same precise relationship withthe plate cylinder regardless of its condition of skew in order toprovide uniform and even distribution of water and ink. While complexlinkages may be employed between the form rollers and the plate cylinderto aline the same after skewing the plate cylinder, it will beappreciated that such complex linkages and other mechanisms havingdelicate adjustments may in time develop a looseness or a play due towear and vibration and thereby may not achieve the desired contactbetween the form rollers and the plate cylinder.

Accordingly, a general object of the present invention is to provide amounting arrangement for a plate cylinder and associated form rollers ina printing press which is economical in construction and which assuresmore ac curate and reproducible positioning of a form roller than hasbeen afforded by prior mounting arrangements.

Another object of the invention is to provide a mounting arrangement ofthe above type which is capable of accurate and consistent operationover a long period of time and which avoids complicated linkages thatmay, as a result of useage, develop looseness or play.

A more specific object of the invention is to mount the form rollers onmounting plates biased against a reference ring coupled to the platecylinder so that the form rollers follow the skewing movement of theplate cylinder and maintain an even and parallel relationship with theprinting cylinder in all of its possible positions of adjustment.

A further object of the invention is to provide a mechanism in such apress capable of automatic return of a form roller to an unalteredrelationship with a skewed plate cylinder following throw-oil.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawings, in which:

FIGURE 1 is a fragmentary elevational view, somewhat diagrammatic, of aprinting press for carrying out the invention;

FIG. 2 is an enlarged, fragmentary setcional view taken along the line2-2 of FIG. 1 in the direction of the arrows and showing the mounting ofthe opposite end of the plate cylinder in the frame of the press;

FIG. 3 is a fragmentary sectional View of a side elevation of theprinting press, with the side frame removed and with portions brokenaway to show the relationship of the various form rollers with theprinting plate cylinder;

FIG. 4 is a partial sectional view taken along the line 4-4 of FIG. 3showing the mounting of an ink form roller as related to a ring carriedby the plate cylinder;

FIG. 5 is a partial sectional view taken along the line 5-5 of FIG. 3and showing the relationship of the form roller to an ink drum and itsmounting plate;

FIG. 6 is a partial sectional view taken along the line 6-6 of FIG. 3and showing the connection of a throw-off cylinder and the mountingplate for the ink form rollers.

While the invention is susceptible to various modifications andalternative constructions, the preferred embodiment of the invention isshown in the drawings and described in detail hereinafter. It is to beunderstood, however, that the present invention is not limited to such adisclosure, but aims to cover all modifications and alternativeconstructions falling within the spirit and scope of the invention asexpressed in the appended claims.

The invention will be shown and described as used on units of offsetprinting presses of the perfecting type. The paper web runs between twoco-acting blanket cylinders, and the ink impression or image carried oneither cylinder is imprinted simultaneously on both sides of the web.Presses for printing a high quality product of several colors, mayconsist of several units in a line with the web running consecutivelythrough each unit which applies a specific color thereon. It isnecessary for the imprint of each color to be placed on the webprecisely in register with the imprints of other colors, so that thefinal product will be a sharp and true reproduction of the originalcopy. It sometimes happens that errors are made in preparing or mountingthe printing plate or that the cylinders of successive press units arenot precisely parallel. When a cylinder is adjusted to compensate itaffects the relationship of the associated members which must becorrespondingly adjusted to maintain the proper cooperative relationshipbetween them.

FIG. 1 of the drawings illustrates diagrammatically the structure usedin practicing the invention as embodied in the lower half of a unit of apress 10 in which both sides of a web are printed simultaneously. Theweb W passes between blanket cylinders 11 and 12 which apply the inkimages to the web. The blanket cylinders run in contact with the platecylinders 13, 14 and receive the inked images from plates held on theplate cylinders by suitable grippers. The plates are moistened and thena film of ink of desired color is applied to the receptive areas inaccordance with the usual practice followed in offset printing. A pairof side frames 15, provides support for the various elements in properrelation to carry out the printing operation or to perform otherfunctions which will be described in the following paragraphs. Flangemembers 15a formed at right angles to the side frames provide structuralreinforcement.

Ink is supplied by an ink fountain, designated generally as 18, fromwhich it is dispensed in regulated amount to a series of rollersdesignated generally at 16,

which transfer the ink to ink drums 23, 24. Form rollers 26, 27, 29, 30are interposed between drums 23, 24 and plate cylinders 14, and areadjusted to uniform longitudinal contact and desired pressure forapplication i of ink to the printing plate. A special mounting isprovided for the ink form rollers and it is this mounting whichcomprises part of the invention for maintaining alinement of theserollers with the plate cylinder.

To dampen the surface of the plate before the ink is applied to it amoistening arrangement, shown generally at 17 is used, including ashallow pan or mountain 28 and a fountain roller 28a. The rollertransfers moisture to drum 31 which in turn contacts form roller 32which rolls on the the surface of the plate. It is important that theliquid be applied uniformly over the entire surface of the printingplate and consequently form roller 32 is adjustably mounted so that itcan be set against the plate with uniform longitudinal contact atdesired pressure. The mounting which will be described includes meansfor maintaining alinement of the axis of the form roller with the axisof the plate cylinder.

It is customary practice in a design of offset printing units of thetype disclosed herein, to mount both ends of the plate cylinder andblanket cylinder in the side frames in eccentric bushings. The purposeis to provide the adjustability needed to accurately aline the axes ofthese cylinders with other members of the press and further to providethrow-off so that printing plates or blankets can be changed. Such typeof mounting, well known in the art, permits adjustment of the platecylinder when the printed image is out of register by a small fractionof an inch. Such adjustment may be adequate to produce necessaryregistration without the burdensome task of correcting the position ofthe plate on the cylinder and may be done during operation of the pressso that results can be immediately observed by inspection of the imageprinted on the web.

When necessary, adjustment for such registration is obtained by a slightrotation of the eccentric mounting at one end of the plate cylinder sothat its axis, shown at 19 in FIG. 2, is slightly cocked or skewed. Thesupporting shaft or journal 34 for plate cylinder 14 is rotatablysupported by a bearing 35, which is mounted in a sleeve or bushing 36received in a bore 37 in side frame for limited rocking movement. Asshown in FIG. 2, the bore of bushing 36 is eccentric to its outersurface so that axis 19 of plate cylinder 14 is slightly offset from thecenter of bore 37. Thus the axis 19 is positionable in an arc aboutcenter 20 when sleeve 36 is rotated. Circular plate 54 bolted to the endof shaft 34 serves as a retainer for hearing 35.

The mounting for the journal on the opposite end of cylinder 14 is alsoshown in FIG. 2, corresponding parts being indicated by the samenumerals with subscript a. This mounting is similarly rockable and islocked in position after all members of the press have been properlyalined.

For the purpose of rockably positioning eccentric bushing 36, a coverplate 38 is securely fastened to the end of the bushing. At the edge ofthe cover plate is an integral arm 39 coupled to a connector 64 by a pin65. The connector is secured to the end of a thrust rod 62. The outerend of the rod is also threaded for reception in a captive nut 63 whichis rotatably mounted in the flange 15a of the side frame and which iscoupled to a handwheel 61. Rotation of the handwheel resulting in axialmovement of the rod 62 rotates the eccentric bushing 36 to a desiredangular position, shifting the end of axis 19 of plate cylinder 14 'to aslightly skewed position. The handwheel may be turned in eitherdirection and in practice a correction of up to 0.015 inch can be madein the position of certain areas of the image printed on the web. Thesmall skewing movement is within the tolerance of the bearing 35, so itis not necessary to provide any realinement of this bearing.

It is important to have the ink and the water uniformly distributed overthe entire plate so that all areas of the plate operate under the sameconditions for uniform color density. It has been found that skewing aplate cylinder as little as 0.015 inch produces misalinement of theplate cylinder and form rollers affecting the uniformity of inking. Bymounting the form rollers in the manner shown in the drawings anddescribed here after, the axes of the form rollers are maintained at alltimes precisely parallel with the axis of the plate cylinder.

The present invention contemplates a novel and simplified arrangementfor causing the form rollers, such as the ink form rollers 26 and 27, toclosely follow the skewing movement of plate cylinder 14 and thus tomaintain parallelism and uniform contact with the plate cylinder.Referring to FIGS. 2 and 3, it will be noted that a reference ring 75,having an outside diameter the same as that of the plates on the platecylinder 14-, is attached to bushing 36 so that its axis coincides withthe axis 19 of the plate cylinder and so that its outer surface 78 isalways in alinement with the surface of the plates. The outer surface ofthe ring, moving whenever the bushing is turned, thus becomes areference for the surface of the plates for all positions of the platecylinder.

For the purpose of coupling one end of each of the form rollers 26, 27to the reference surface of the ring to maintain proper running relationwith the plate cylinder, the sockets of the respective form rollers aresupported in mounting plates which are pivotally mounted about the shaft68 of ink drum 23. As shown in FIG. 5, the socket 42 which supports theform roller 26 is attached to a plate 40 on one side of the drum axis. Aplate extension or arm 83 on the other side of the drum axis is engagedby suitable biasing means for holding the end of the plate 87 in contactwith surface 78 of ring 75, permitting the mounting plate to rock aboutthe shaft of the drum and carry the end of the form roller with it, whenit is necessary to skew the axis of the plate cylinder to obtainregistration of the printed image on the Web. Adjustable mounting forthe form rollers also provided at the opposite ends except that at theopposite ends the mounting plates engage fixed stops and thus remainrelatively stationary as the plate cylinder is skewed; consequently itis not necessary that the opposite ends of the rollers be shown ordescribed in detail.

The other form rollers are mounted similarly to roller 26. As shown inFIG. 3 form roller 27 is supported on a plate 41 which is pivotallymounted on the shaft 68 of ink drum 23, while rollers 29, 30 aresupported on plates 40a, 41a which are pivotally mounted on the shaft68a of ink drum 24. Bushings indicated at 79, and 790, may be interposedbetween the mounting plates and the drum shafts on which they aremounted. Such shafts are in turn rotatably supported in the frame bybushings 73 (see FIG. 5). The mounting plates are biased into engagementwith ring 75 at 87, 88 and contact is maintained by means of suitablesprings 85, 86, which bear against arms 83, 84 of the mounting plates.Arms 83, 84 are bifurcated and drilled to receive a pin 33 which extendsbetween the two parts 57, 58 to form a connection with the biasingmechanism. FIG. 6 shows a shaft 93 supported by bushing 25 in frame 15.The shaft extends to the frame on the opposite side where it issimilarly mounted and provides a fixed base for creating the biasingforce to maintain contact between plates and ring 75. This shaft 93 alsosupports a double throw eccentric or cam 74 by means of which the formrollers can be bodily separated from the plate cylinder 14 when requiredduring operation of the press.

Mechanism for biasing the plates into engagement with ring 75 appears inFIGS. 3 and 6, details of the mechanism being shown at 69 and 70 in FIG.6. As described above the arm 83 on the mounting plate 40 is bifurcatedand fitted with a special pin 33. This pin has flat sides at the centerbut is cylindrical at the ends so it can turn between the two parts 57,58 with respect to the arm 83. A hole is drilled at right angles throughthe flat of this pin. A stud 71 passes through this hole and is threadedinto the elongated portion of a strap fitting 72 that is rotatablyfitted to the eccentric 74 on shaft 93. A bushing 76 surrounding thestud is pressed by the spring 85 and engages one of the flat sides ofpin 33 as shown in FIG.

6. Telescoped within the bushing 76 is a second bushing 77 which engagesthe opposite end of the spring. Spring member 85 is thus containedbetween the flanges of bushings 76 and 77. To complete the assembly, anut 80 is threaded onto the outer end of stud 71 and serves as a meansfor adjusting the position of bushing 77 and hence the force exerted bythe spring. In short, the biasing force of spring 85 urges bushing 76into engagement with the flat on pin 33 which in turn is secured in arm83 of mounting plate 40, tending to rotate the plate in a clockwisedirection as shown in FIG. 3, holding it resiliently in contact withring 75 at the region 87. Springs 85, 86 are separately adjustable.

When it is necessary to skew the plate cylinder in a direction causingplate 40 to rotate in a counter clockwise direction, arm 8-3 moves in adirection away from fixed shaft 93 so that the spring 85 is furthercompressed, maintaining contact between the plate and ring 75. Uponmovement of the cylinder in the reverse direction, the spring expands torotate mounting plate 40 clockwise to hold it in engagement with thering. A small clearance, shown at 67 in FIG. 6, is built into thearrangement during assembly. This clearance permits adequate clockwiserotation of the mounting plate 40 to insure that the mounting plate willat all times remain in contact with ring 75. It should be noted that themechanism 70 acts upon the arm 84 of the mounting plate 41 in a similarmanner to maintain contact with ring 75 at the region 88. The plateedges at 87, 83 are preferably in a cylindrical locus to provide welldefined line contact with the ring.

Means are provided to permit adjustment of the roller sockets withrespect to their mounting plates thereby to permit adjustment of the setof the roller with respect to the plate cylinder 14 and ink drum 23.Once a form roller has been adjusted into a position which provides thedesired set, the socket is locked in this position on the plate. Duringthe subsequent movement of the mounting plate, carrying the end of theform roller with it, the set is maintained, thereby insuring a uniformfilm of ink across the width of the plate.

FIGS. 4 and 5 show the construction of the sockets 42 at the ends of theform rollers. Here it will be noted that the bearings 46 on the shafts47 at the end of form rollers 26 and 27 are secured in housings which inturn are attached to adjustable brackets 48 which are adjustablypositioned on mounting plates 40, 41. Bracket 48 is held against themounting plate by a nut 52 on a stud 50 which extends through aclearance opening 51 in the bracket terminating in a head member 49.When nut 52 is loosened to relieve the clamping force, bracket 48 may beshifted as required to make necessary adjustments of the form roller. Asshown in FIG. 4, adjustment is obtained by turning an adjusting screw 44which is captively held in a sleeve 53 fixed to the bracket 48 and whichthreadedly engages the head member 49 on stud 50. By turning screw 44,the bracket 48 is moved on its mounting plate. Two such screws areprovided, spaced from one another, the second being indicated at 43. Byplaying the screws against one another, the form roller can be properlyset against both of the adjacent membars. The socket assemblies 42 shownin FIGS. 4 and 5 are substantially identical except that the adjustingscrew 44 is between the mounting plate and the side frame of the pressas shown in FIG. 5 and on the other side of the mounting plate in FIG.4.

During operation of offset printing presses of the type described, it isnecessary to bodily separate the ink and water form rollers from thesurface of the plate cylinder. The mechanism shown includes means forproducing this separation and also for moving the form rollers back intocontact with the plate cylinder, without affecting the setting oralinement of the rollers. Independent controls are provided so that inkform rollers may be separated at one time and the water form rollerseparated at a different time. The throw-off operation may be performedwhen the plate cylinder is in alinement or when it is in a skewedposition. In prior structures it has been ditficult to regain accuratealinement between form rollers and a plate cylinder following athrow-off operation, when the form rollers were returned into contactwith the plate cylinder. The disclosed arrangement eliminates thisdiificulty, because the mounting plates will always return to engagementwith the surface 78 of ring 75, which is equivalent to the platecylinder surface, thus assuring automatic realinement of form rollersand plate cylinders. Throw-off of the ink form rollers is hereaccomplished by a power cylinder 96, which is connected to a lever 92 ona throw-off shaft 93. Plunger 91 of cylinder is actuated by movement ofa piston within the cylinder and may be moved in or out as desired byapplying pressure fluid to the appropriate end of the cylinder. Thisarrangement is shown in FIG. 1 while details of the mechanism will befound in FIGS. 3 and 6. A double-throw cam 74, with the throwspositioned approximately 180 degrees apart, is keyed to shaft '93. Thestrap fittings 72 for connecting the plates with the means for biasingthe plates against the ring 75 are fitted on to the cams so thatassembly 69 is opposite to assembly 70. When cylinder '90 is actuated,cam action results in separating the arms 83, 84 on plates 41), 41 ordrawing them closer together. When the mounting plates are in thepositions shown in FIG. 3, a movement of cam shaft 93 will result inclockwise rotation of plate 41 and counterclockwise rotation of plate40, breaking contact at 87, 85. It should be understood that carn shaft93 extends entirely across the press and actuates mechanism on theopposite side of the press which is similar to that shown, so thatthrow-off occurs equally at both ends of the form rollers. When thepress operator desires to bring form rollers again into contact with theplate cylinders and ink drums, the actuating cylinder 90 is actuated torotate the cam shaft 93 back t its starting position re-establishingcontact with the surface of ring 75 at 87 and 88, thus restoring theoriginal alinernent or set.

Although ink is applied to the printing plate by pairs of form rollerseach in contact with a drum, moisture is applied to the surface of theprinting plate by the single water form roller 32 as shown in FIGS. 1and 3. Maintenance of alinement of this form roller with the platecylinder while in slightly skewed position is similar to the arrangement42 described above, and is obtained by ad justably mounting the formroller 32 in a socket 142 attached to plate 144 which is pivotallysupported on the shaft 168 of drum 31. An arrangement 169, similar to 69which applies a biasing force to plate 41, is attached to strap fitting172, biasing plate against the ring 75 at point 187. Throw-off of theform roller 32 may be actuated by power means 190 (FIG. 1), which isconnected to a lever 192 on the shaft 193 causing cam 174 and strapfitting 172 to rotate resulting in clockwise rotation of plate 140 asseen in FIG. 3. This lifts roller 32 off of the surface of the printingplate on plate cylinder 14. By means of a similar mechanism (not shown)at the opposite side of the press, the roller is lifted or separated forits full length. Reverse rotation of the shaft 193 restores uniformcontact between the form roller 32 and the plate cylinder and alinementis maintained because plate 146 again contacts ring 75 at 187.

For the purpose of moving the cylinder 14 axially, means are providedfor transmitting axial motion to the sleeve 36. Thus, referring to FIG.2, the cover plate 38, which is secured to the eccentric sleeve 36, hasan integral stub shaft 154 which extends axially outward and which isthreaded, preferably with a thrust-transmitting thread of acmeconfiguration. The stub shaft is engaged by an internally threaded wormwheel 155 driven by a worm 156 which, in turn, rotated by an adjustingdrive motor 157. Rotating the motor in one direction or the other causesthe eccentric sleeve 36 in which the shaft of the cylinder is captive,to be moved in opposite directions. Thus it is seen that the sameeccentric sleeve assembly is capable of bringing about two distincttypes of adjustment, namely, the skewed shifting of the printingcylinder and the associated form rollers via the ring 75 and the endwiseshifting of the printing cylinder by means of the threaded stub shaft154.

It will be apparent in view of the foregoing that the objects, set forthat the outset, have been achieved effectively and at low cost. Not onlymay a high degree of registration accuracy be achieved by the skewing ofthe printing cylinder, but the automatic accompanying skewing of theform rollers which occurs insures that the uniformity of application ofthe water and ink films will remain unaffected. Thus the press may bequickly and easily adjusted under practical press room conditions.

When the form rollers are returned to contact after being separated orthrown-off, the condition of alinement of the form rollers with a skewedplate, and the adjustment or set of the form rollers with both theprinting cylinder and ink drums is automatically re-established.

While the term mounting plates has been applied to the mounting membersfor the form rollers, such as that shown at 40, the members may take anydesired physical shape consistent with their pivoted supportingfunction.

We claim as our invention:

1. In a printing press, the combination comprising a pair of spaced sideframes, a cylinder for holding printing plates, means for journallingthe cylinder in said frames, said journalling means including means atone end for laterally shifting the cylinder axis for skewing adjustment,an ink drum journalled in said frames and radially spaced from the platecylinder, a form roller disposed for rolling engagement with saidcylinder and said drum, a mounting plate supporting one end of the formroller and pivoted for swinging movement substantially about the drumaxis, a reference ring at said one end of the cylinder coaxial with thecylinder and coupled to the cylinder to maintain the coaxialrelationship in all positions of skew, and means for maintaining theform roller mounting plate in engagement with the ring so that the formroller follows the cylinder over its range of skewing adjustment.

2. The combination defined in claim 1 in which the reference ring issecured to the shifting means.

3. The combination defined in claim 1 in which the shifting meansincludes an eccentric sleeve interposed between the end of the cylinderand the side frame and in which the reference ring is secured to thesleeve.

4. The combination defined in claim 1 in which the outer diameter of thereference ring is substantially equal to the diameter of the surface ofthe plates on the plate cylinder.

5. The combination defined in claim 1 including throwotf means forrotating the mounting plate in a first direction to separate the platefrom said reference ring and said form roller from said cylinder and forrotating said plate in a reverse direction to re-engage said plate withsaid ring and said form roller with said cylinder.

6. The combination defined in claim 4 in which the mounting plate isformed to provide line contact with the reference ring and in which anactuator is provided for separating the mounting plate from the ringwhile overcoming the biasing force.

7. In a printing press the combination comprising a pair of spaced sideframes, a cylinder for holding printing plates, means for journallingthe cylinder in said side frames, said journalling means including meansat one end of the cylinder for laterally shifting the cylinder axis forskewing adjustment, a plurality of ink drums journalled in said framesand radially spaced from the plate cylinder, form rollers interposedbetween the ink drums and the plate cylinder, each form roller having amounting plate supporting one end thereof and pivoted for swingingmovement substantially about the axis of the associated ink drum, areference ring at one end of the cylinder coaxial with the cylinder andcoupled to the cylinder for maintaining the coaxial relationship in allpositions of skew, means for biasing the mounting plates against thereference ring to establish axial alinement of form rollers and cylinderso that the form rollers follow the skewing movement of the cylinder andmaintain uniform contact with the plates thereon over the range of skewadjustment, and means for simultaneously swinging the roller mountingplates in a direction away from the ring to achieve throw-off betweenthe form rollers and the cylinder.

8. The combination defined in claim 7 in which the biasing force formaintaining each roller mounting plate in engagement with the ring isindividually adjustable.

9. In a printing press the combination comprising a pair of spaced sideframes, a cylinder for holding printing plates, means for journallingthe cylinder in said side frames, said journalling means including meansfor shifting one end of the cylinder axis for skewing adjustment, drumsjournalled in said frames and radially spaced from the plate cylinder,form rollers rollingly interposed between the drums and the platecylinder, each form roller having a mounting plate supporting each endthereof and pivoted for swinging movement about the axis of theassociated drum, a reference ring at one end of the cylinder coaxialwith the cylinder and coupled to the cylinder for maintaining thecoaxial relationship in all positions of skew, each mounting platehaving a ring-engaging surface, means for biasing the ring-engagingsurfaces of the mounting plates against the reference ring so that theform rollers follow the cylinder and maintain contact with the platesthereon over the range of skew adjustment, means on the mounting platesbetween the rollers and the ring-engaging surfaces for individualadjustment of roller pressure, and means for simultaneously swinging theroller mounting plates in a direction away from the ring to achievetemporary throw-off between the form rollers and the cylinder.

References Cited UNITED STATES PATENTS 2,762,295 9/1956 Varga et al.101-148 XR 1,755,278 4/1930 Strain 101348 2,763,207 9/1956 McWhorter101-348 2,750,883 6/1956 Dietrich et a1 101348 ROBERT E. PULFREY,Primary Examiner.

H. DINITZ, Assistant Examiner,

